They work

They work. easy to install and if you are making your own bridges out of bone, it is really easy to get power to the strings by routing a small groove between each one and wrapping a wire around each ferrule.

Does the job well.

I am a beginning luthier and I wanted to alter the sound of my Mexican Fender Jazz Bass as much as I could by feeding the strings though the body. These ferrules gave me what I was looking for.

The adjustments to my bass may be far from perfect, but Stew-Mac delivered, as always. I'm happy with these ferrules. They aren't as large as the ones on American-made Fender basses that have string-through bodies, but they are the right size to be tasteful and functional.

Every bass should have these

These are great ferrules, perfect match for American Fender style string through ferrules.

I build high end customs and do lots of upgrades/hot-rodding for my clients. One of the first things I suggest to a client wanting better sustain and tone is a bridge upgrade and STRING THROUGH MODIFICATION. This is where the "piano tones" come from. Every bass I have (8) are string through, and I've performed this mod on 50 or more basses with great results.